IV percentile

IV percentile measures the percentage of trading days over the past 52 weeks where implied volatility was lower than it is today. Like IV rank, it's expressed from 0 to 100.

A reading of 80 means current IV is higher than it was on 80% of trading days over the past year.

IV percentile vs IV rank: Both measure how elevated current IV is relative to recent history, but differently. IV rank compares to the annual high and low extremes. IV percentile counts actual days. This makes IV percentile more statistically robust , a single extreme IV spike (like a flash crash or earnings blowout) can distort IV rank but has less impact on IV percentile.

When IV percentile gives a more accurate picture: If a stock had one massive IV spike to 150% last year due to a short squeeze, its IV rank might show 30 (looks cheap) while IV percentile shows 72 (actually elevated on most days). IV percentile better reflects the typical trading environment.

When IV rank is more useful: IV rank is faster to interpret intuitively and more widely used as a quick screening tool. For most trades, IV rank above 50 is the signal , IV percentile confirms it.

Example: If TSLA's IV was below today's level on 195 of the past 252 trading days: IV percentile = 195 / 252 × 100 = 77. Options are elevated relative to most of the past year.

Related terms: IV rank, implied volatility, IV crush, Vega

Try it on Stryke: Compare IV rank and IV percentile side by side in the Options Screener.

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